Psychotherapy researchers and practicing clinicians alike have stressed the importance of the therapeutic relationship or alliance for optimal psychotherapy process and outcome. The development of a positive therapeutic alliance has proven to be one of the most consistent predictors of successful therapy outcome in adult psychotherapy across a wide range of therapeutic orientations and outcomes. Yet, despite strong evidence of the predictive value of alliance for adult psychotherapy process and outcome, there has been little empirical work on alliance in child psychotherapy, especially in mental health service settings. The proposed study is designed to address this gap in the literature by investigating: (1) predictors of both child and parent therapeutic alliances; (2) the relationships between child and parent alliances and therapy engagement; and (3) the relationships between child and parent alliances and treatment outcomes in a sample of approximately 150 children and their parents receiving mental health services at one of four community clinics in Los Angeles. Multi-level or hierarchical linear modeling will be used to investigate client-level and therapist-level predictors of both child and parent alliance, and to investigate the predictive value of child and parent alliance for therapy engagement and outcomes over two years post-intake. The proposed research will increase our understanding of the relationship between process and outcome in child and adolescent psychotherapy, and may lead to improved care for children and their families seeking mental health services.